Alert archive / California / Frost Advisories in 2016

Frost Advisory 11, NWS Eureka, CA

September 21, 2016Mendocino County, Trinity County, California

NWS Eureka, CA issued this frost advisory at Sep 21, 2016, 2:20 PM PDT for Mendocino County, Trinity County, California. It took effect at Sep 21, 2016, 11:00 PM PDT. It was in force for 7 hr.

The area

The counties it named.

The facts

Issued
Sep 21, 2016, 2:20 PM PDT (21:20 UTC)
In effect from
Sep 21, 2016, 11:00 PM PDT
Expired
Sep 22, 2016, 5:59 AM PDT
In force
7 hr
Issued by
NWS Eureka, CA

Counties Mendocino County, CA, Trinity County, CA

The radar

The Eureka (Bunker Hill) radar (KBHX), 100 km from the middle of the area, began a volume at 21:17 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The nearest sounding before it

Medford/Jackson, OR (KMFR), launched 12:00Z, 9.3 hours before the alert went out and 262 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Medford/Jackson, OR at 12:00Z on 2016-09-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Medford/Jackson, OR at 12:00Z on 2016-09-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -33 square meters per square second.1939587897Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1168 m above ground
0-6 km bulk shear
62 kt
0-1 km storm-relative helicity
-33 m²/s²
0-3 km storm-relative helicity
99 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

235 
WWUS76 KEKA 212120
NPWEKA

URGENT - WEATHER MESSAGE
NATIONAL WEATHER SERVICE EUREKA CA
220 PM PDT WED SEP 21 2016

CAZ107-108-110-111-221300-
/O.NEW.KEKA.FR.Y.0011.160922T0600Z-160922T1600Z/
NORTHERN TRINITY-SOUTHERN TRINITY-NORTHWESTERN MENDOCINO INTERIOR-
NORTHEASTERN MENDOCINO INTERIOR-
220 PM PDT WED SEP 21 2016

...FROST ADVISORY IN EFFECT FROM 11 PM THIS EVENING TO 9 AM PDT
THURSDAY...

THE NATIONAL WEATHER SERVICE IN EUREKA HAS ISSUED A FROST
ADVISORY...WHICH IS IN EFFECT FROM 11 PM THIS EVENING TO 9 AM PDT
THURSDAY. 

* LOW TEMPERATURES...MID 30S.

* LOCATIONS INCLUDE...COVELO...WILLITS...HAYFORK...DOUGLAS
  CITY...PEANUT.

* FOR A DETAILED VIEW OF THE HAZARD AREA...VISIT
  HTTP://WWW.WRH.NOAA.GOV/MAP

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A FROST ADVISORY MEANS THAT FROST IS POSSIBLE. SENSITIVE OUTDOOR
PLANTS MAY BE KILLED IF LEFT UNCOVERED.

&&

$$
1 follow-up statement
097 
WWUS76 KEKA 221259
NPWEKA

URGENT - WEATHER MESSAGE
NATIONAL WEATHER SERVICE EUREKA CA
559 AM PDT THU SEP 22 2016

CAZ107-108-110-111-221400-
/O.CAN.KEKA.FR.Y.0011.000000T0000Z-160922T1600Z/
NORTHERN TRINITY-SOUTHERN TRINITY-NORTHWESTERN MENDOCINO INTERIOR-
NORTHEASTERN MENDOCINO INTERIOR-
559 AM PDT THU SEP 22 2016

...FROST ADVISORY IS CANCELLED...

THE NATIONAL WEATHER SERVICE IN EUREKA HAS CANCELLED THE FROST
ADVISORY. 

OBSERVATIONAL TRENDS INDICATE ONLY A FEW INTERIOR LOCATIONS HAVE
REACHED LOW ENOUGH TEMPERATURES FOR POSSIBLE FROST FORMATION.
GIVEN THE VERY ISOLATED/MARGINAL CHANCES REMAINING FOR THIS TO
OCCUR, THE ADVISORY WAS CANCELLED.

$$

Nearby

Frost Advisories in California, 2016Every frost advisory in 2016

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.